Extreme pressure gear lubricant



2,830,024 Patented Apr. 8, 19 58 ice 2,830,024 EXTREME PRESSURE GEAR LUBRICANT Paul R. Chapman, Crystal Lake, and Allan A. Manteuifel,

Union, 111., assignors to The Pure Oil Company, Clucago, 111., a corporation of Ohio N Drawing. Application September 9, 1953 Serial No. 379,285

3 Claims. (Cl. 252-46.7)

The present invention relates to lubricating compositions having extreme pressure characteristics with improved storage stability and good performance characteristics and, more particularly, it relates to lubricants for gears, such as hypoid gears, transmissions, and differentials.

It is known to prepare extremepressure additives for use in lubricating oil compositions which have the ability of imparting to the lubricating composition resstance to sudden heavy (shock) loading conditions in metal-tometal owrking parts or prolonged heavy loading as in metal working operations, such as cutting, deep drawing, and tappingof metals. Additives which contain The extreme pressure gear lubricants of the present invention comprise two components-first, an extreme pressure concentrate and, second, the mineral oil portion of the composition, principally a solvent refined Mid-Continent mineral oil. The extreme pressure concentrate is composed of a sulfur and phosphorous carrier and a chlorinated extreme pressure additive.

The sulfur and phosphorous carried may comprise a sulfurized non-fat material, such as Metalyn; a phossulfur either in free form or in loosely bound form, principally made by sulfurizing a fatty body or fatty oil with or without subsequent phosphorizing the sulfurized prodnot so produced, are among the principal ingredients used for this purpose. The incorporation of small amounts of fatty oil and sulfur in lubricating oils to compound an extreme pressure lubricant does not always result in a finished product which is compatible under all conditions of use or storage or which exhibits the preferred characteristics of an extreme pressure lubricant. Often the addition of specialized additives for the purpose of.

adjustment of the final viscosity, stability, or appearance of the finished product upsets one or more of the other desirable physical properties or performance characteristics to the end that extreme pressure gear lubricants which do not exhibit these difiiculties and which are more versatile, more easily manufactured, extremely stable during storage, and exhibit good performance characteristics at reduced cost are often very difiicult to compound.

The invention comprises specifically the discovery of a formulation for extreme pressure lubricants which includes as a part thereof a sulfur and/or phosphorous carrier along with an extreme pressure additive of the chlorinated type incorporated in a mineral oil which overcomes the difliculties of incompatability and storage stability While at the same time exhibits good performance characteristics. The extreme pressure lubricants of the present invention are characterized by their case of manufacture and their ability to withstand the extreme conditions to which such lubricants are subjected in use.

Accordingly, the principal object of the present invention is to provide an extreme pressure lubricating composition including a sulfur and/or phosphorous carrier and an extreme pressure additive of the chlorinated type.

A second object of this invention is to provide an ex treme pressure gear lubricant comprising a mineral oil, a sulfur and phosphorous carrier, and an extreme pressureadditive of, the chlorinated type.,

A third object of this invention is to provide an extreme pressure, gear lubricant composition including a sulfur carrier and a phosphorous carrier, a viscosity index improver, and a chlorinated high treme pressure additive.

, molecular. weight ex- 7 I methyl esters of tall oil, and it phorized fatty oil, such as phosphorized glyceryl trioleate; a sulfurized and phosphorized fatty oil, such as sulfurized-phosphorized lard oil; su-lfurized mineral oils; sulfurized alkyl esters of animal and vegetable fatty acids where the alkyl group comprises methyl, ethyl, propyl or butyl groups; and combinations of these sulfur-containing constituents alone or in solution in an oleaginous substance. For example, the reaction product of petroleum and fattyoils and a phosphorous-containing-material prepared in accordance with United States Patent 2,142,998 may be used. The sulfurize'd-phosphorized base described in United States Patent 2,211,306 is an excellent extreme pressure lubricant base for use in accordance with this invention. Many of thesesulfurized and/ or phosphorized bases are expensive and diflicult to compound into a compatible composition. A particularly useful combination of extreme pressure bases to be used in accordance with this invention con'iprises'sulfurized Metalyn and phosphorized glyceryl trioleate. In particular this combination along with the chlorinated extreme pressure agents has been found to be a suitable substitute for such more expensive and difficultly compounded bases as dibenzyl disulfide in extreme pressure compositions.

The Metalyn referred to above is a trade name for is prepared by the methyl esterification of tall oil acids under elevated pressure followed by distillation of the ester. This product, now being manufactured by the HerculesPowder Sompany, will have the following characteristics:

Percent methyl esters of rosin acids .45.0 (typical). Percent methyl esters of fatty acids 47.0 (typical). Percent unsaponifiable modified AOCS Appearance at 20/ 30 C Clear and free of foreign matter.

In sulfurizing the Metalyn, elemental sulfur in the form of finely powdered flowers of sulfur is sifted in small increments into a kettle containing the Metalyn heated to about 275 to 285 F., while being vigorously agitated by a mechanical agitator. Although it is preferred to react 93 parts of Metalyn with 7 parts by weight of sulfur, theratio of Metalyn to sulfur may suitably vary from about parts Metalyn-15 lyn-3 parts sulfur.

7 After thefaddition of the sulfur to the Metalyn is com-l pleted, the temperature of the mixture is raised to 350 During the initial stages .of the 'sulfun'zation reaction, it is important to keep the temperature about:20 to 30 below the flash point of Metalyn (385 F.). Reaction parts sulfur to 97 parts Meta is allowed "to proceed for approximately 7 to 8 hours when it should be complete as indicated by a copper strip test. Shorter reaction periods are possible where efiiciently heated kettles areavailable. During the final stages of the reaction,the temperature may be allowed to rise to 375 F. to insure complete reaction. The: end of thereaction is determined by immersing. a polished copper 'strip'in'a sample of the product for one minute at 300 F. ,If the copper'strip remains bright, the reaction is completed. As previously'pointed out-, mechanical agitation and not air-blowing'is used during the entire reaction period. -T he finished reaction product will have the followingcharacteristics:

API gravity 1 8.0 Lbs. per gallon 8.45 Percent sulfur; 6.26 SUS viscosity at 210 F 56.2

Although this is the preferred product, it will be understood that the sulfurizedMetalyn may contain from approximately 3 to percent of'sulfur. Where smaller amounts of sulfur are used, the reaction time and/or temperature may be reduced. Similarly, where larger amounts 'of sulfur are used, longer reactiontimes will be required in order to obtain a finished product. Higher temperatures will hasten the reaction time, but temperatures in excess of 400F. should be avoided.

It will be understood that other esters of tall oil acids such as the ethyl, propyl, butyl, and amyl may be sulfurized in the same manner as Metalyn to form one constituent of'the E. P. base. If desired mixtures of the several esters may be used instead of a single ester in order to obtain desired viscosity, pour point and other properties in the finished oil. The ethylene, propylene and butylene glycol dioleates may also be used.

In preparing phosphorized glyceryl trioleates, it ispreferred to use glyceryl trioleate having the following specifications:

max; 8% saturated max Phosphorus sesquisulfide is used for phosphorization because of the uniformity of the resulting products. Other sulfides of phosphorus such as phosphorus penetasulfide cause undesirable polymerization. It is important thatapure form of phosphorus sesquisulfide be used since impure material produces 'a dust-like sediment in the finished product. Pure phosphorus sesquisulfide has a uniformly light yellow color, whilethe impure material is characterized by smallparticles of grayish material running uniformly through the entire sample.

In the preparation, 195 parts by weight of glyceryl trioleate are heated in a kettle to 185 to 195 F. with vigorous mechanical agitation. To the heated material is added 5 parts by weight offinely powdered phosphorus sesquisulfide in small increments. When the total amount of phosphorus sesquisulfide is added, the temperature of the mixture is raised to 220 to 230 F. and the tempera-- ture maintained at this level until the reaction is complete, which should require about 4 to 5 hours. The completion of the. reaction is determined by immersing a copper'strip in'a sample of'reaction mixture at the temperature of 210 F. for 3 minutes. bright, the-reaction is completed. During the entire reaction, mechanical agitation, and not air-blowing, is, used. The fini'shed'phosphorized glyceryl trioleate will have the following characteristics: g V

If the strip. remains 4 API gravity.. 19.7 Lbs. per gallo 7.79 Weight percent sulfur 0.97 Weight percent phosphorus 1.26 5 SUS viscosity at 210 F 67.7

The chlorinated extreme pressure additive may include any chlorinated hydrocarbon, naphthalene compound, parafiin compound, or 1wax compound, such as chlorinated naphthalenes, known under the trade names of Halowax 1020 and Halowax 1014, or combinations of chlorinated naphthalene and chlorinated parafiinsyknown under the trade name of Chlorowax 40. 'These chlon'nated derivatives of naphthalene may contain from 10 to 40 percent of chlorine. Other chlorinated ring and chain compounds maybe used, including chlorinated petroleum wax, chlorinated aliphatic hydrocarbons, and alpha-chlornaphthalene.

Variousother'additives maybe incorporated including, for example, pour point depressants, anti-corrosive compounds, other extreme pressure additives, viscosity index improvers, solubilizers, etc. One particularly advantageous additive comprises a viscosity index improver, such as the proprietary product 'known as Acryloid 150, which product comprises a pour depressant for the oil and is available commercially as a polymeric fluid. Chemically, this product is a methyl methacrylate polymer having the following properties: specific gravity, 60/60, 0.89; viscosity at 210 F., 3100 SUS; viscosity at 100 F., 27,500 SUS.

The-mineral oil'portion of the composition may comprise any lubricating oil or refined fractions thereof. The combination of a 150 viscosity bright stock and 170 viscosity neutral of the high V. I. type has been found particularly useful in preparing gear oil lubricants in accordance with this invention. The bright stock and neu: tral are proportioned to give a finaLviscosity to the finished lubricant inthe range of 80-90 SUS at 210 4 R All componentsof the gear oil composition may be blended together at temperatures from 185 to 195 F.

The blending may take place in short periods of 15 to minutes to produce a stable satisfactory gear lubricant. v The following examples are given as typical formulations representing combinations of preferred sulfur carriers, chlorinated compounds, and other additives:

(Percent by weight composition) i 13.0% (5.0 sulfurized Metalyn--l0.8 wt. percent of total;. 1.0 phosphorized glyceryl trioleatev 2.2 wt. percent of total 0.3% Halowax 1020 p 0.5% Acryloid 59.0% ,150 vis. Mid-Continent solvent refined bright stock 27.2% vis. Mid-Continent solvent refined neutral 100.0% total 7 10.0% 3.0 sulfurized Metalyn-7.5 wt. percent of total; 1.0 phosphorized glyceryl trioleate-2.5 wt. percent of total t 0.2% 10.0 Halowax 1020, 0.11 wt. percent of total;

' 1.0 Chlorowax 40, 0.09 wt. percent of total assets;

r V (3) termine the storagestability or compatibility of Halo-. lf -i d and phosphorized l d fl waxes with extreme pressure concentrates. Thecom- 0.3% Halowax 1020 v positions tested were prepared by adding different amounts 0.5% Acryloid 150 r of Halowax 1014 and Halowax 1020 to sulfurized Meta- 21.0% 150 vis. Mid-Continent solvent refined brigh 5 lyn, phosphorized glyceryl trioleate, and a mixture comz1.o% exii f from 150 vis. bright stock (Mid-Conf Sulfurized Metal and phsphfized glywyl fluent) eate extreme pressure base. These concentrates were 45.2% 170 vis. Mid-Continent solvent refined neutral prepared by heatmg the extreme pressure compound to I V v 1 r 10 220-230 F. and subsequenfly adding the Halowaxes with 100 0% t tal 7 vigorous stirring. The blends were stirred until cooled to The Physical and chemical characteristics of the comabout 150-1600 Storage tests conducted under these ponems used in en grade extreme Pressure lubriconditions of high concentration are much more indicam am h i T bl I; tive of stability of the products than tests conducted in TABLE I I Characteristics of the components used blending the 90 grade E. P. lubes Viscosities,p F., SUS Per- Per- Flow Per- API Flask, Fire, V. I. Pour, cent cent pt., Color cent p. gr.,

Halowax 1020 Light 53. 3 1. 69-1. 74 Halowax 1014 V Pale yellow. 56. 5 1. 76-1. 88 S-P lard oil. 525 7. 23 0. 245 Extract from brt. stock 9 +80 2. 29 15o vis. hrt. stock. 100 2 8: 170 vis. neutral 103 0 0. 18

In Table II a comparison is made of extreme pressure compositions (Example 1) containing a sulfurized-phoswhich mineral oil is part of the composition. The results are shown in Table III.

T imken bench test 7 Blend 2 Percent by weight composition metJGTO E. P. base. Dibenzyl (llsnlfida V B-P lardoil H e Halowax 1020 Halowaxlnu Acryloid 1 Extract from brt. stk

150 bright stock neutral Viscosity (SUS): 210 F 130F 100 F 7 Vi m ii'y-indpx Timken, 800 R. P. M.:

Beam load Obs.) Pressure (p. s. i.) Modified SAE:

Weight loss Ring appearanm 19 OK OK phorized lard oil and Acryloid 150 and,(Example 2) containing dibenzyl disulfide in addition to the extreme pressure base as exemplary of products which meet the viscosity, V. L, Timken, and Modified SAE tests. Example 3 shows a composition wherein the sulfur-containing carrier is a sulfurized Metalyn-phosphorized glyceryl trioleate extreme pressure base giving acceptable viscosity, V. 1., Timken, and modified SAE tests. Examples 4 through 9 show compositions including chlorinated extrerne pressure additives in accordance with this invention which meet the physical requirements of extreme pressure lubricants. In order to further demonstrate the present invention, a series of tests were conducted tovde- TABLE III Compatibility of Halowaxes with E. P. concentrates Blend 11 12 13 14 15 i 16 Parts by weight composiiii 11- o v Halowax 1014 Halowax 1020 Sulfurized Metalyn Phosphorized GTO Mgtalyn/ GTO E The Halowaxes may be incorporated in concentrations from 0.3 weight percent to.9.0 weight percent to .form compatible mixtures .withthe sulfur-phosphorous extreme pressure base.) TheHalowaxes may be present in concentrations ranging from 0.3 to 0.5 weight percent of finished product including the minera'l'oil carrier.

The proportions of ingredients usedin compositions prepared in accordance. with the present invention may vary somewhat from the exact weightpercent compositions shown in the examples.- The sulfurized and/or phosphorized extreme pressure base'may be present in from about 10 to 13 weight percent. The amount of viscosity index improverrepresented by Acryloid 150 may vary from 0.4 to 1.5 weight percent "depending on the amount required to bring the composition tolthe desired viscosity index. Further the percent of chlorinated extreme pressure compound may vary from about 0.1 tov 0.3 weight percent or as high as 0.5 weight percent.

The mineral oil can make up the balance of the. compo.-

sition. One advantage of the invention is that by substi tuting the chlorinated compounds for the dibenzyl disulfide, a composition can be prepared with less cost and by using less material's. Furthermore, the ditficulties in handling and compounding dibenzyl disulfide are avoided.

What is claimed is: V l. A lubricant additive consisting of a mixture of about 3-5 parts by weight of sulfurized methyl esters of tall oil acids, said sulfurized product containing about3% to 10% by weight of sulfur acid being obtained by the:

reaction. of methyl. esters of talloil acids with elemental sulfur at a temperature -30 F. below the flash point of said esters until a product is obtained which is noncorrosive to a polished copper strip when in contact therewith for'about: one minute at a temperature of 300 F., about 1 part by weight of phosphorized glyceryl trioleate, said phosphorized product containing about 0.97 weight percent of sulfur acid about 1.26 weightpercent of phosphorus and being obtained by reacting glyceryl trioleate with phosphorus' sesqui'sulfide at a temperature of about 220 to 230 F. until a product is obtained which is non-corrosive to a polished copper strip when in contact therewith for about three minutes at a temperature of 210 F., and, about 0.1 to 0.5 part by weight ofa chlorinated naphthalenecontaining about 10 to 40% by weightofchlorine, said mixture beingcharacterized by its stability during storage at room tern peratures and at a temperature of 32 F.

2. A lubricant additive consisting of aumxture'of about 13.0 .parts by weight of a sulfurandphosphorus-containing base consisting of about 5.0 parts of sulfurized 1 methyl esters of tall oil acids containing about 6.26 weight percent of sulfur and being obtained by the reaction ofsaid methyl esters of tall oil acids with elemental sulfur at a temperature of 20-30 F. below the flash point. of

0.97 weight percent of sulfurand about 1.26 weight percent of phosphorus sesquisulfide at a temperature of about 220 to 230 F. until a product is obtained which is non-corrosive to a polishedcopper strip when in contact therewith for about three minutes at 210 F. and about 0.5 parts by weight of a chlorinated naphthalene containing about 10% to 40% by weight of chlorine, said mixture being characterized by its stability during storage at room temperature and at a temperature of 32 F.

3. An extreme pressure lubricant composition C011. sisting of about 59.0 weight percent of 150 vis. Mid-Continent solvent refined bright stock, about 27.2 weight percent of ,170 vis. Mid-Continent solvent-refined neutral, about 13.0,weight. percent of an extreme pressure base consisting of a mixture about 5.0 parts by weight of sulfurized methyl esters of tall oil acids containing about 6.26weight-percent of sulfur and being obtained by the reaction of said methyl esters of tall oil acids with elemental sulfur at a temperature 20 to 30 F. below the flash point of said esters until a product is obtained which. is non-corrosive to a polished copper strip when in con about 0.97 weight percent of sulfur and about 1.26 weight percent of phosphorus and being obtained by reacting glyceryl trioleate with phosphorus sesquisulfide at a temperature of about 220 to 230 F. until a product is obtained which. is non-corrosive to a polished copper strip when in contact.therewithforabout threeminutes at 210 F. and 0.3 part by weight of a chlorinated naphthalene containing about 10% to 40% by weight of chlorine and about 0.5 part by weight of methyl methacrylate having a viscosity at 210 F. of 3100 SUS and a viscosity of F. of 27,500 SUS, said lubricant composition being characterized by its storage stability and ability topass the Timken and Modified SAE' tests.

ReferencesCited in the tile of thispatent Beretvas July 7, 1953 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 2,830,024 4 April 8, 1958 Paul R. Chapman et a1.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 1, line 23, for "resstance" read resistance line 25, for "owrking" read working column 2, line 8, her "carried" read carrier line 38, for "Sompany" read Company line 55, "for the designation "D4445' read D445 column 6, lines 5 and 6, for "composing" read comprising columns 5 and 6, Table II, under the column headed "'7", opposite "Pressure (p.s.i.)" for "19.000" read 19,000

Signed and sealed this 27th day of May 1958.

Attest: I y. I

L H. KAR AXLINE ROBERT C. WATSON Attesting Officer 7 Conmissioner of Patents 

1. A LUBRICANT ADDITIVE CONSISTING OF A MIXTURE OF ABOUT 3-5 PARTS BY WEIGHT OF SULFURIZED METHYL ESTERS OF TALL OIL ACIDS, SAID SULFURIZED PRODUCT CONTAINING ABOUT 3% TO 10% BY WEIGHT OF SULFUR ACID BEING OBTAINED BY THE REACTION OF METHYL ESTERS OF TALL OIL ACIDS WITH ELEMENTSL SULFUR AT A TEMPERATURE 20-30*F. BELOW THE FLASH POINT OF SAID ESTERS UNTIL A PRODUCT IS OBTAINED WHICH IS NONCORROSIVE TO A POLISHED COPPER STRIP WHEN IN CONTACT THEREWITH FOR ABOUT ONE MINUTE AT A TEMPERATURE OF 300*F., ABOUT 1 PART BY WEIGHT OF PHOSPHORIZED GLYCERYL TRIOLEATE, SAID PHOSPHORIZED PRODUDT CONTAINING ABOUT 0.97 WEIGHT PERCENT OF SULFUR ACID ABOUT 1.26 WEIGHT PERCENT OF PHOSPHORUS AND BEING OBTAINED BY REACTING GLYCERYL TRIOLEATE WITH PHOSPHORUS SESQUISULFIDE AT A TEMPERATURE OF ABOUT 220* TO 230*F. UNTIL A PRODUCT IS OBTAINED WHICH IS NON-CORROSIVE TO A POLISHED COPPER STRIP WHEN IN CONTACT THEREWITH FOR ABOUT THREE MINUTES AT A TEMPERATURE OF 210*F., AND ABOUT 0.1 TO 0.5 PART BY WEIGHT OF A CHLORINATED NAPHTHALENE CONTAINING ABOUT 10 TO 40% BY WEIGHT OF CHLORINE, SAID MIXTURE BEING CHARACTERIZED BY ITS STABILITY DURING STORAGE AT ROOM TEMPERATURES AND AT A TEMPERATURE OF 32*F. 